The invention relates generally to nonwoven cloth-like fabrics and more particularly concerns health care laminates which incorporate one or more layers of elastic or adhesive nonwoven webs formed from a polar polymer.
Conventional nonwoven health care fabrics generally have been restricted to laminates of non-polar, relatively high melting temperature thermoplastics. This restriction is the result of limitations imposed by standard treatments designed to impart anti-static properties and alcohol repellency to such fabrics for use in health care applications. Such repellency treatments require soaking the fabric in a fluorocarbon surfactant dissolved in a polar alcoholic solvent and subsequent processing of the material through drying cans which expose the fabric to significant heat. Hultman et al. U.S. Pat. No. 4,115,605 discloses such a standard treatment.
Low-crystallinity polymers, such as poly (ethylene-vinyl acetate) (EVA), which possess desirable adhesion, softness, drape, and hand, usually contain polar groups and cannot be treated with polar alcoholic solvents. These polar groups absorb the polar solvent and retain its undesirable odor even after drying. In addition, the heat of the drying process often degrades these polar polymers such that they pass into the liquid phase and harden into a film upon cooling. As a result, prior art fabrics for health care applications have not been able to use low crystalline, polar polymers and have had to sacrifice the softness and desirable textural characteristics that those polymers possess.